User's Manual

Two Channel 400MHz Cell Enhancer
User Handbook
Handbook N.-50-128501HBK Issue No:-A
Date:-12/08/2005
Page:-
19 of 39
4.3 30dB Power Monitor (07-012501)
4.3.1 Description
The purpose of these couplers is to tap off known portions (usually 15-30dB) of RF signal
from transmission lines at the antenna ports, either resistively or by induction, and to
combine them, for example through splitter units for different purposes (alarms/monitoring
etc.), whilst maintaining an accurate 50Ω load to all ports/interfaces throughout the specified
frequency range. They are formally known as directional couplers as they couple power
from the RF mainline in one direction only.
Various constructional techniques are used depending on the specification required. These
include microstrip, stripline, coaxial cable and capacitive types.
4.3.2 Technical Specification
PARAMETER SPECIFICATION
Frequency range: 350 – 550MHz
Insertion Loss: <0.3dB
Coupling level: -30dBc
Rejection: N/A
Weight: <200gms
Connectors: N type, female
operation: -10°C to +60°C Temperature
range:
storage: -20°C to +70°C
4.4 ¼Watt 0- -30dB Switched Attenuator (10-000701)
4.4.1 General Application
In many practical applications for Cell Enhancers etc., the gain in each path is found to be
excessive. Therefore, provision is made within the unit for the setting of attenuation in
each path, to reduce the gain.
4.4.2 Switched Attenuators
The AFL switched attenuators are available in two different types; 0 – 30dB in 2 dB steps
(as in this case), or 0 – 15dB in 1 dB steps. The attenuation is simply set using the four
miniature toggle switches on the top of each unit. Each switch is clearly marked with the
attenuation it provides, and the total attenuation in line is the sum of the values switched
in. They are designed to maintain an accurate 50 impedance over their operating
frequency at both input and output.